Inverter building using Wiseguys Power board and the Nano drive board


Author Message
KeepIS

Guru

Joined: 13/10/2014
Location: Australia
Posts: 1860
Posted: 04:53am 05 May 2025      

I decide to look at the %PWM for a 3 second starting load that pulls 30kW Input, a 600A Pulse Input @ 100Hz raised the PWM from 74% @ 16A to 88% at 600A.

So allowing for voltage sag and other loss errors at these loads currents, and the percentage of PWM at the time the load first starts over the time period.

I'm estimating 28kW DC input and around 19kW AC start load, which would not trip my Inverter AC current limit setting of 89A in the Nano, also allowing for Nano AC current trip calculations which will be out a bit because of the nature of the AC load presented at this high over current trip point.      

More Tests.

DC current waveforms at 4kW looks almost identical to the perfect AC output sine wave, the only visible difference is DC current is twice the frequency, there is not a single glitch or waveform disturbance on either waveform.

A 4kW load, mainly Resistive, sees AC output total harmonic distortion @ 1.12%, PF 0.996, a perfect Sine wave and no shed light flickering when rapidly switching another 2.6kW on/off across the output.

Switching 2.6kW on and off at idle causes no light flickering, there is no way to tell anything is being placed on the Inverter by listening, only by looking at Inverter metering or the DSO display of DC amps as AC sinewave doesn't show any change without sync capture.

FYI 2.1kW AC workshop machine loads: DC IN: 100A pulsed, 38.6A "Average", PWM 76%
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Edited 2025-05-06 10:34 by KeepIS